Gardening

Bud-Hardy Forsythias for Northern Gardeners

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A typical forsythia grown in the North blooms only at the base due to its poor bud hardiness. Photo: extension.umaine.edu

The spectacular spring bloom of the forsythia (Forsythia spp.), with its countless yellow bells stretching right to the tip of its branches, is a true harbinger of spring… in moderate climates (zones 6 to 8). Further north, though, it can’t even be counted on to bloom every year.

That’s because the forsythia is one of those shrubs whose stems and leaf buds are very hardy (most will grow with no damage to zone 3), but whose flowers are not nearly as cold resistant. The result? In zones 3 and 4, the shrub blooms only at its base most years, where it was covered in snow all winter. (Snow is an excellent insulator.) What a disappointment!

Even in zone 5, you can’t always count on a forsythia to bloom abundantly every year: there are good years and bad, depending on how severe the winter was.

Unfortunately, many nurseries continue to offer varieties of forsythia that are not reliably bud hardy, like F. ovata ‘Ottawa’ and F. x intermedia ‘Lynwood Gold’, still the two most widely available varieties in most northern nurseries… and also the varieties most prone to disappoint their buyers.

Bud-Hardy Forsythias

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Forsythia ‘Northern Gold’ is a reliable bloomer in zones 4 and 5 and usually blooms well even in zone 3.

Yet there are hardier forsythias, at least where flower buds are concerned. The varieties listed below should bloom every year in zones 4 and 5 and most will bloom well even in zone 3 too, unless the previous winter was particularly nasty. Here are the ones to look for:

  • ‘Meadowlark’
  • ‘Northern Sun’
  • ‘Northern Gold’
  • ‘New Hampshire Gold’
  • ‘Vermont Gold’

Note that you can’t trust plant labels when it comes to bud hardiness. Both ‘Ottawa’ and ‘Northern Gold’ may well be labeled zone 3, because the shrub itself is hardy to zone 3. But of the two, only ‘Northern Gold’ is bud hardy in zone 3.

If your forsythia continues to disappoint you, year after year, the solution is therefore simple: yank it out and plant a variety better suited to your climate. Problem solved, permanently!

How to Grow a Forsythia

Of course, for a forsythia bloom well, you still have to offer it suitable growing conditions. But fortunately that’s rarely a problem: forsythias are particularly easy shrubs to grow.

For abundant bloom, give your plant full sun. It will bloom in partial shade, but less densely. Almost any well-drained soil will do, from poor to rich and from acid to alkaline, but avoid sites that are exceptionally dry: forsythias like moderate moisture at all times.

Any pruning, if necessary, should be done immediately after the plant finishes blooming, therefore in late spring. If you prune yours in the fall, for example, or during the winter, you will sacrifice part or all of upcoming season’s bloom.

Forsythia: so easy to grow… but for bloom, you have to plant the right variety!

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

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